1. Field of the Invention
This invention relates, generally, to devices that hold down movable objects so that they are not displaced by windstorms and the like. More particularly, it relates to an earth anchor apparatus having a water jet that facilitates its introduction into the ground.
2. Description of the Prior Art
U.S. Pat. No. 4,044,513 to Deike discloses an earth anchor that is driven into the earth by a hollow ram that enters the trailing end of the earth anchor. A concrete slurry is pumped through the hollow ram as it is retracted and a plug presses the concrete into crevices and pores surrounding the hole.
A mobile home anchor is disclosed in U.S. Pat. No. 4,023,314 to Tanner. Water is introduced into the earth through a hollow anchor post having a pair of diametrically opposed arms that are folded back during insertion of the apparatus into the earth. The arms are deployed when the anchor reaches its desired depth.
U.S. Pat. No. 5,833,400 to Wamsher is introduced into a borehole while in a vertical position. It burrows into the earth until the anchor is lodged in a position that is normal to the borehole.
The known earth anchors are characterized by relatively complex structures that include moving parts. Such earth anchors are expensive to manufacture. Some of them are also unreliable because their structural complexity can cause deployment failures or deployments that are less than optimal.
What is needed, then, is a reliable earth anchor having a simple structure, no moving parts, and a low price.
However, in view of the prior art considered as a whole at the time the present invention was made, it was not obvious to those of ordinary skill how the needed earth anchor could be provided.
The earth anchor of this invention performs the function of holding various items to the surface of the earth so that the wind or other externally applied force cannot displace said items.
The structure of the novel earth anchor includes a thin, elongate base having a longitudinal axis of symmetry, a transversely disposed leading end and a transversely disposed trailing end. A nozzle attachment means is positioned at the leading end of the elongate base and is disposed normal to a plane of said base.
The base may be flat or it may have a slight convexity or warp formed therein as a result of the molding process used to manufacture it. Whether perfectly flat or slightly warped, the base presents a thin profile that eases its entry into the earth.
The distal end of an elongate anchor means of flexible construction is secured to the elongate base. The elongate anchor means may be provided in the form of an anchor strap, rope, wire, cable, or the like. The proximal end of the elongate anchor means is positioned above the surface of the earth when the distal end thereof is positioned at a preselected depth below the surface of the earth so that the proximal end can be pulled upon to set the novel earth anchor against retraction.
The nozzle attachment means is adapted to releasably engage a leading end of an elongate jet pipe means. The elongate jet pipe means is positioned substantially parallel to the elongate base when the leading end of the elongate jet pipe means is releasably engaged to the nozzle attachment means. The elongate base and jet pipe means together form a pipe anchor assembly as a whole.
Means are provided for introducing a liquid fluid under pressure into a trailing end of the jet pipe means so that the elongate base is inserted into the earth by first positioning the elongate base in substantially normal relation to the surface of the earth with its leading edge in abutting relation to the surface. Liquid fluid under pressure is then introduced into the trailing end of the jet pipe means and pressure is applied to the trailing end of the jet pipe means while the liquid fluid is flowing from the leading end of the jet pipe means. The liquid fluid flowing from the leading end of the jet pipe means forms a borehole in the earth. The jet pipe means is withdrawn when the earth anchor reaches a preselected depth. The proximal end of the anchor strap is then pulled upon to set the earth anchor at said depth. More particularly, pulling on the elongate anchor means causes the earth anchor to rotate about its trailing end until it deploys into a substantially horizontal position where it is substantially perpendicular to the borehole.
The earth anchor presents substantial resistance to displacement from the preselected depth when so deployed so that preselected items may be tied to the proximal end of the elongate anchor means to secure the preselected items to the surface of the earth.
The preferred method for installing an earth anchor at a preselected depth below the surface of the earth includes the step of providing a thin, elongate base having a longitudinal axis of symmetry, a transversely disposed leading end and a transversely disposed trailing end. Further steps include securing the distal end of an elongate anchor means of flexible construction to the elongate base and positioning a nozzle attachment means at the leading end of the elongate base. The steps further include disposing the nozzle attachment means normal to a plane of the elongate base, adapting the nozzle attachment means to releasably engage a leading end of an elongate jet pipe means, positioning the elongate jet pipe means substantially parallel to the elongate base when the leading end of the elongate jet pipe means is releasably engaged to the nozzle attachment means, dimensioning the elongate anchor means so that a proximal end thereof may be pulled upon when its distal end is positioned at a preselected depth below the surface of the earth, injecting a liquid fluid under pressure into a trailing end of said jet pipe means, inserting the pipe anchor assembly as a whole into the earth by positioning said elongate base in substantially normal relation to the surface of the earth with its leading edge in abutting relation to said surface, by introducing liquid fluid under pressure into the trailing end of the jet pipe means, applying pressure to the trailing end of the jet pipe means while the liquid fluid is flowing from the leading end of the jet pipe means, retracting the jet pipe means when the elongate base reaches its preselected depth, and pulling upon said proximal end of the anchor strap to cause the elongate base to pivot about its trailing end until it obtains a position substantially perpendicular to the borehole.
In this way, the earth anchor presents substantial resistance to displacement from the preselected depth when so deployed so that preselected items may be tied to the proximal end of the elongate anchor means to secure said preselected items to the surface of the earth.